In the past there has been a strong desire to recess and conceal various types of audio visual equipment within the confines of a room or vehicle which is used for presentations. While some projectors are mounted permanently on structures within the room, others in more sophisticated settings have been concealed or hidden in the walls, floor or ceiling of the structure.
As is well known in theaters, the motion picture projectors are usually concealed in a separate enclosed room behind a glass partition at the back of the theater so that the projected image can be placed on a screen within the presentation area. This method is quite adequate with respect to high powered projection equipment, such as movie projectors or slide projectors having long focal length lenses.
The situation changes drastically when it is desired that television projectors or computer display projectors are to be used. These devices, when they are used in presentation rooms, theaters or auditoriums must be quite large to match the environment in order to be able to project a display which is large enough for the audience to easily see. It is normally required that these projectors be positioned closer to the screen and in front of the screen to reduce or eliminate distortion in the corners or outer areas of the display. As a result, it is generally necessary to position these types of projectors essentially in the middle of the room directly in front of the screen. This means the projector is elevated above the floor of the auditorium usually on a support tower or in some cases they can be suspended from the ceiling and generally in the middle of the floor area. Naturally, this type of positioning for a projector is quite distracting and destroys the decor or ambiance of the area, especially when the equipment is not in use.
The present inventor has been a pioneer in the attempt to solve this problem by devising lift structures which can be attached to the ceiling of the area and which can allow the projector to be remotely raised or lowered from the ceiling surface. When use of the projector is required the projector can be lowered on cables to the required "show" position. A projector of this type which is suspended below the ceiling naturally is still quite obtrusive and consequently this type of suspension is undesirable.
Attempts have been made by the present inventor to recess the projector within the ceiling but because of the mass of the mechanism required for the lifting device it has been difficult up to this point to be able to provide a satisfactory arrangement for this purpose. The primary limitation with this type of lifting device is due to the fact that there is usually a very small dimensional clearance available between the ceiling of the auditorium or room and the above floor or roof structure. In many cases, this clearance is no more than fifteen to eighteen inches and in many cases this amount of clearance prevents any type of lift mechanism, especially those involved with a television projector, to be concealed within the ceiling.
This patent application is directed to a new solution to eliminate the problems which have been encountered in the past with this type of mechanism and for this reason this application is directed to a very unique lifting structure which has considerable value and importance in this field.